Urine Formation

Q. Describe the process of urine formation in kidneys.

Q. Describe the process of urine formation in kidneys.

Q.

Which part of the nephron is impermeable to salts?

1. DCT

2. PCT

3. Ascending limb of loop of Henle

4. Descending limb of loop of Henle

Q.

Wastes are removed from the bodies of living organisms only in the form of urine.

1. True

2. False

Q.

Name the following :

The duct that transports urine to the urinary bladder.

Q. Match the items in column 1 with those in column 2

Column 1	Column 2
Air spaces	Hair
mammary gland	sebaceous glands
"Goose-flesh"	Rudimentary in males
Traces of urea	Races of hot countries
more numerous sweat pores	Gray hair
oily secretion	sweat

Q. Explain the structure of nephron.

Q.

Which of the following is not reabsorbed during urine formation?

1. Glucose

2. Amino acids

3. Salts

4. Urea

Q.

Which of the following is not reabsorbed during urine formation?

1. Glucose

2. Salts

3. Urea

4. Amino acid

Q. Why is excretion necessary? Name the common excretory substances in our body. [3 MARKS]

Q. During urine formation, reabsorption mainly takes place in the _________ of nephron.

1. collecting duct
2. Bowman's capsule
3. glomerulus
4. tubular part

Q.

The correct sequence of urine formation in human body is:

1. Selective reabsorption → Glomerular filtration → Tubular secretion

2. Glomerular secretion → selective secretion → tubular reabsorption

3. Glomerular filteration → selective reabsorption → tubular secretion

4. Tubular filtration → Selective reabsorption → Tubular secretion

Q. Diuretics are substances that help eliminate water from the body. Few volunteers were taken into the study, all of which had same mass. They drank nothing for eight hours before the test and urinated just prior to ingesting the test substance. The three substances (water, caffeine, and salt) were tested on three separate days. The results are shown in the tables below.
Table 1

Volunteer	Amount of caffeine ingested (in 100 ml water)	Volume of urine collected after 1 hour
A	50 mg	302 ml
B	100 mg	492 ml
C	150 mg	667 ml
D	200 mg	863 ml

Table 2

Volunteer	Amount of sodium chloride ingested (in 100 ml water)	Volume of urine collected after 1 hour
A	0.9 g	201 ml
B	1.8 g	162 ml
C	2.7 g	125 ml
D	3.6 g	82 ml

Table 3

Volunteer	Volume of water ingested	Volume of urine collected after 1 hour
A	100 ml	230 ml
B	200 ml	240 ml
C	300 ml	252 ml
D	400 ml	263 ml

Which of the following substances could be classified as a diuretic?

1. Caffeine
2. Sodium
3. Both A and B
   
4. Water
   
5. Both A and C
   

Q.

Micturition takes place

1. When stretch receptors of urinary bladder are stimulated

2. When the brain transmits motor impulses

3. Contraction of urinary bladder and relaxation of sphincter

4. All of the above